MLA
Galleries, Brady's National Photographic Portrait. Confederate General John Byron Gordon. E. and H. T. Anthony, 1861. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 16, Folder 27. https://digital.library.emory.edu/purl/245q83bkrk-cor.
APA, 6th edition
Galleries, B. N. P. P. (1861). Confederate general John Byron Gordon (Box 16, Folder 27) [Cartes-de-visite (card photographs)]. E. and H. T. Anthony; Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/245q83bkrk-cor.
Chicago
Galleries, Brady's National Photographic Portrait. “Confederate General John Byron Gordon.” Cartes-de-visite (card photographs). Civil War Collection. New York City, NY: E. and H. T. Anthony, 1861. Box 16, Folder 27. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/245q83bkrk-cor.